<Page
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Grid Height="99" Width="504">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="1*"/>
            <ColumnDefinition Width="2*"/>
        </Grid.ColumnDefinitions>

        <Button Grid.Column="0">label set by tag content</Button>
        <Button Grid.Column="1" Content="label set by 'content' attribute"/>

    </Grid>
</Page>